function base64_encode(str) {
    var c1, c2, c3;
    var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    var i = 0, len = str.length, string = '';

    while (i < len) {
        c1 = str.charCodeAt(i++) & 0xff;
        if (i == len) {
            string += base64EncodeChars.charAt(c1 >> 2);
            string += base64EncodeChars.charAt((c1 & 0x3) << 4);
            string += "==";
            break;
        }
        c2 = str.charCodeAt(i++);
        if (i == len) {
            string += base64EncodeChars.charAt(c1 >> 2);
            string += base64EncodeChars.charAt(((c1 & 0x3) << 4)
                | ((c2 & 0xF0) >> 4));
            string += base64EncodeChars.charAt((c2 & 0xF) << 2);
            string += "=";
            break;
        }
        c3 = str.charCodeAt(i++);
        string += base64EncodeChars.charAt(c1 >> 2);
        string += base64EncodeChars.charAt(((c1 & 0x3) << 4)
            | ((c2 & 0xF0) >> 4));
        string += base64EncodeChars.charAt(((c2 & 0xF) << 2)
            | ((c3 & 0xC0) >> 6));
        string += base64EncodeChars.charAt(c3 & 0x3F)
    }
    return string
}

function base64_decode(str) {
    var c1, c2, c3, c4;
    var base64DecodeChars = new Array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
        -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62,
        -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,
        -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
        15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,
        26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
        43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
    var i = 0, len = str.length, string = '';

    while (i < len) {
        do {
            c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff]
        } while (i < len && c1 == -1);

        if (c1 == -1)
            break;

        do {
            c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff]
        } while (i < len && c2 == -1);

        if (c2 == -1)
            break;

        string += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));

        do {
            c3 = str.charCodeAt(i++) & 0xff;
            if (c3 == 61)
                return string;

            c3 = base64DecodeChars[c3]
        } while (i < len && c3 == -1);

        if (c3 == -1)
            break;

        string += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));

        do {
            c4 = str.charCodeAt(i++) & 0xff;
            if (c4 == 61)
                return string;
            c4 = base64DecodeChars[c4]
        } while (i < len && c4 == -1);

        if (c4 == -1)
            break;

        string += String.fromCharCode(((c3 & 0x03) << 6) | c4)
    }
    return string;
}
module.exports = {
    'base64_encode': base64_encode,
    'base64_decode': base64_decode 
};